Sensor unit and image processing device

ABSTRACT

A sensor apparatus includes a photosensitive sensor, a cover, and a moving mechanism. The photosensitive sensor includes a first lens and a second lens which focus on a photosensitive element. The cover includes a first slit arranged on an optical axis of the first lens and a second slit arranged on an optical axis of the second lens. The moving mechanism is configured to move the photosensitive sensor and the cover relative to each other so that the second slit is arranged on the optical axis of the first lens.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/122,668, filed on Dec. 15, 2020, which is based upon and claims thebenefit of priority from. Japanese Patent Application No. 2020-101684,filed on Jun. 11, 2020, the entire contents of which are incorporatedherein by reference.

FIELD

Embodiments described herein relate generally to sensor units and imageprocessing devices.

BACKGROUND

As an image processing device, an image forming device which forms animage on a sheet is used. The image forming device includes a sensorunit (apparatus) which detects a presence of a person. The sensor unitis required to prevent a decrease in detection sensitivity. The sensorunit is required to be able to adjust a detection range.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an image processing device of at least oneembodiment;

FIG. 2 is a block diagram of the image processing device according to atleast one embodiment;

FIG. 3 is a side cross-sectional view of a first state of a sensor unit(apparatus) according to at least one embodiment;

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3 ;

FIG. 5 is an explanatory diagram of a detection range of the sensor unitin the first state;

FIG. 6 is aside cross-sectional view of the sensor unit in a secondstate;

FIG. 7 is an explanatory diagram of a detection range of the sensor unitin the second state;

FIG. 8 is a side cross-sectional view of the sensor unit in a thirdstate; and

FIG. 9 is an explanatory diagram of a detection range of the sensor unitin the third state.

DETAILED DESCRIPTION

An object to be solved by an exemplary embodiment is to provide a sensorunit (apparatus) and an image processing device (processor) capable ofpreventing a decrease in detection sensitivity and adjusting a detectionrange.

A sensor unit of at least one embodiment includes a photosensitivesensor, a cover, and a moving mechanism. The photosensitive sensorincludes a first lens and a second lens which focus on a photosensitiveelement. The cover includes a first slit arranged on an optical axis ofthe first lens and a second slit arranged on an optical axis of thesecond lens. The moving mechanism is configured to move thephotosensitive sensor and the cover relative to each other so that thesecond slit is arranged on the optical axis of the first lens.

Hereinafter, a sensor unit and an image processing device of at leastone embodiment will be described with reference to the drawings.

FIG. 1 is a front view of the image processing device of at least oneembodiment. In the present application, a Z direction, an X direction,and a Y direction of the Cartesian coordinate system are defined asfollows. The Z direction is a vertical direction and a +Z direction isan upward direction. The X and Y directions are horizontal. The Xdirection is a width direction of an image forming device. A +Xdirection is to a right direction with respect to the image formingdevice. The Y direction is a depth direction of the image formingdevice. The +Y direction is a direction from the front to the back ofthe image forming device. A θ direction is a circumferential directionin the X direction. A +θ direction is a rotation direction of aright-hand screw traveling in the X direction.

The image processing device of at least one embodiment is an imageforming device 1. The image forming device 1 performs a process offorming an image on a sheet. The sheet may be paper. The image formingdevice 1 includes a control panel 11, a scanner portion 12, an imageprocessing unit, a sheet supply portion 15, and a controller 16.

The control panel 11 includes an operation unit and a display portion.The operation unit is provided with various keys, a touch panel, and thelike, and accepts user operations. The display portion displays varioustypes of information.

The scanner portion 12 reads image information of an object to be copiedbased on brightness and darkness of light and generates an image signal.

The image processing unit of at least one embodiment may be an imageforming unit 13. The image forming unit 13 forms a toner image based onan image signal from the scanner portion 12 or the outside. A tonerimage is an image formed of toner or other material. The image formingunit 13 transfers the toner image onto the surface of the sheet. Theimage forming unit 13 includes a fixing device 14. The fixing device 14heats and pressurizes the toner image transferred to the sheet to fixthe toner image on the sheet.

The sheet supply unit 15 supplies the sheets one by one to the imageforming unit 13 at the timing at which the image forming unit 13 formsthe toner image.

FIG. 2 is a block diagram of the image processing device.

The image forming device 1 includes a central processing unit (CPU) 91,a memory 92, an auxiliary storage device 93, and the like connected by abus, and executes a program. The image forming device 1 functions as adevice including the control panel 11, the scanner unit 12, the imageforming unit 13, the sheet supply unit 15, and the like by executing aprogram.

The CPU 91 functions as the controller 16 by executing a program storedin the memory 92 and the auxiliary storage device 93. The controller 16controls the operation of each functional unit of the image formingdevice 1.

The auxiliary storage device 93 is configured by using a storage devicesuch as a magnetic hard disk device or a semiconductor storage device.The auxiliary storage device 93 stores information.

A sensor unit (apparatus) 19 will be described.

The image forming device 1 includes the sensor unit 19 illustrated inFIG. 1 . The sensor unit 19 is located at a predetermined height in the+Z direction from the floor surface. For example, the sensor unit 19 islocated at the corners of the image forming device in the −X directionand the −Y direction. The sensor unit 19 detects a person existing in avicinity of the image forming device 1.

FIG. 3 illustrates a first state of the sensor unit of the embodimentand is a side cross-sectional view taken along the line III-III of FIG.1 . The sensor unit 19 includes a photosensitive sensor 20 illustratedin FIG. 3 , a cover 18, and a moving mechanism 48 illustrated in FIG. 1.

The photosensitive sensor 20 includes a photosensitive unit E and a lensunit L illustrated in FIG. 3 .

The photosensitive unit E detects light rays. The photosensitive unit Eincludes a plurality of photosensitive elements 26 and 27. The pluralityof photosensitive elements 26 and 27 are arranged side by side in aplane perpendicular to an optical axis 30 of the photosensitive sensor20. The photosensitive sensor 20 may be a pyroelectric sensor. Thepyroelectric sensor includes pyroelectric elements as the photosensitiveelements 26 and 27. The pyroelectric element uses the pyroelectriceffect to detect infrared rays emitted by a person. The pyroelectriceffect is a phenomenon in which the electric charge of a ferroelectricsubstance increases or decreases due to a temperature change caused byinfrared rays. If the photosensitive unit E detects light rays, thephotosensitive unit E outputs a detection signal.

The lens unit L focuses the incident light rays on the photosensitiveunit E. The lens unit L collects the incident light rays on thephotosensitive unit E. The lens unit L includes a plurality of lenses21, 22, and 23. The plurality of lenses 21, 22, and 23 are the firstlens 21, the second lens 22, and the third lens 23. The plurality oflenses 21, 22, and 23 may be arranged side by side in a circumferentialdirection of a horizontal axis H. The horizontal axis H is parallel tothe X direction and passes through the surface of the photosensitiveunit E. The first lens 21, the second lens 22, and the third lens 23 arearranged side by side in this order from the +Z direction to the −Zdirection.

The optical axis 30 of the photosensitive sensor 20 is orthogonal to theX direction and intersects the horizontal axis H. In the first state ofthe sensor unit 19 illustrated in FIG. 3 , the optical axis 30 of thephotosensitive sensor 20 is inclined by an angle a from the −Y directionto the +θ direction. Optical axes 31, 32, and 33 of the plurality oflenses 21, 22, and 23 are orthogonal to the X direction and intersectthe horizontal axis H. The second optical axis 32 of the second lens 22coincides with the optical axis 30 of the photosensitive sensor 20. Thefirst optical axis 31 of the first lens 21 is inclined by an angle b inthe −θ direction from the second optical axis 32. The third optical axis33 of the third lens 23 is inclined by the angle b in the +θ directionfrom the second optical axis 32. The angle a and the angle b are thesame. In the first state of the sensor unit 19 illustrated in FIG. 3 ,the first optical axis 31 is parallel to the Y direction.

The moving mechanism 48 illustrated in FIG. 1 pivotably supports thephotosensitive sensor 20 around the horizontal axis H. The movingmechanism 48 includes a lever 49. The lever 49 is exposed to the outsideof the image forming device 1. The lever 49 is connected to thephotosensitive sensor 20. If the lever 49 pivots in the 0 direction, thephotosensitive sensor 20 pivots in the 0 direction. The moving mechanism48 is configured to pivot the photosensitive sensor 20 around thehorizontal axis H.

The cover 18 is located between the outside of the image forming device1 and the photosensitive sensor 20 illustrated in FIG. 3 . The cover 18prevents the action of an external force on the photosensitive sensor 20and protects the photosensitive sensor 20. The cover 18 is a part of thehousing of the image forming device 1. The cover 18 may have a flatplate shape and is parallel to the X direction. A normal line 34 on thesurface of the cover 18 is inclined by the angle a from the −Y directionto the +θ direction. In the first state of the sensor unit 19illustrated in FIG. 3 , the optical axis 30 of the photosensitive sensor20 coincides with the normal line 34 on the surface of the cover 18.

The cover 18 has a plurality of slits 41, 42, and 43. The plurality ofslits 41, 42, and 43 penetrate the cover 18 in a thickness direction.The plurality of slits 41, 42, and 43 are long in the X direction andshort in the Y direction. The plurality of slits 41, 42, and 43 are thefirst slit 41, the second slit 42, and the third slit 43. In the firststate of the sensor unit 19 illustrated in FIG. 3 , the plurality ofslits 41, 42, and 43 are respectively located on the optical axes 31,32, and 33 of the plurality of lenses 21, 22, and 23. The first slit 41is located on the first optical axis 31. The second slit 42 is locatedon the second optical axis 32. The third slit 43 is located on the thirdoptical axis 33. In other words, the optical axes 31, 32, and 33 of theplurality of lenses 21, 22, and 23 respectively pass through theplurality of slits 41, 42, and 43. The first optical axis 31 passesthrough the first slit 41. The second optical axis 32 passes through thesecond slit 42. The third optical axis 33 passes through the third slit43.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3 .As illustrated in FIGS. 3 and 4 , the inner surfaces of the plurality ofslits 41, 42, and 43 are formed along the ends of the angles of view ofthe plurality of lenses 21, 22, and 23 in the first state. In the firststate, as illustrated in FIG. 3 , the plurality of lenses 21, 22, and 23are arranged so that the optical axes 31, 32, and 33 pass through theplurality of slits 41, 42, and 43. The ends of the angles of view of theplurality of lenses 21, 22, and 23 are the optical paths farthest fromthe optical axes 31, 32, and 33 among the optical paths of light raysincident on the photosensitive unit E through the plurality of lenses21, 22, and 23.

The inner surface of the first slit 41 is formed along the end of theangle of view of the first lens 21 in the first state. The inner surfaceof the second slit 42 is formed along the end of the angle of view ofthe second lens 22 in the first state. The inner surface of the thirdslit 43 is formed along the end of the angle of view of the third lens23 in the first state. The inner surfaces of the plurality of slits 41,42, and 43 intersect at angles other than perpendicular to the surfaceof cover 18.

The plurality of slits 41, 42, and 43 do not limit the angles of view ofthe plurality of lenses 21, 22, and 23. The incident light rays on thephotosensitive sensor 20 are not limited by the plurality of slits 41,42, and 43. Such configuration prevents a decrease in the detectionsensitivity of the photosensitive sensor 20. The set of optical paths oflight rays incident on the photosensitive unit E through the pluralityof lenses 21, 22, and 23 is the detection ranges 51, 52, and 53 by theplurality of lenses 21, 22, and 23. The plurality of slits 41, 42, and43 do not limit the detection ranges 51, 52, and 53 by the plurality oflenses 21, 22, and 23.

Since the plurality of slits 41, 42, and 43 are elongated, human fingersmay have difficulty in entering. Such a configuration prevents adecrease in detection sensitivity due to contamination of thephotosensitive sensor 20. Since the plurality of slits 41, 42, and 43are elongated, the action of an external force on the photosensitivesensor 20 is prevented. Such configuration improves the reliability ofthe photosensitive sensor 20.

FIG. 5 is an explanatory diagram of the detection range of the sensorunit in the first state. The sensor unit 19 detects a person who is nearthe image forming device 1 as a person who may use the image formingdevice 1. The sensor unit 19 detects a person existing in the detectionranges 51, 52, and 53. In the first state, the first optical axis 31 isparallel to the Y direction. The first detection range 51 by the firstlens 21 extends to infinity, but a first detection distance Da isdetermined by the detection sensitivity of the photosensitive unit E.The detection distance is the distance from the photosensitive sensor 20within which the photosensitive sensor 20 can perform detection. If aperson is within the range of the first detection distance Da, thephotosensitive sensor 20 outputs a detection signal.

In the first state, the second optical axis 32 and the third opticalaxis 33 are inclined from the −Y direction to the +θ direction. Thesecond detection range 52 by the second lens 22 and the third detectionrange 53 by the third lens 23 are finite ranges. The second detectionrange 52 and the third detection range 53 are closer to the imageforming device 1 than the first detection range 51. The photosensitivesensor 20 also outputs a detection signal if a person is in the seconddetection range 52 or the third detection range 53.

As illustrated in FIG. 2 , the photosensitive sensor 20 is connected tothe bus. The controller 16 controls the power supplied to the imageforming unit 13 based on the output signal of the photosensitive sensor20. The power supply mode to the image forming unit 13 includes at leasta normal mode and a power saving mode. In the normal mode, all powerrequired for image formation is supplied. In the power saving mode, thepower supplied to some devices including the fixing device 14 isrestricted. Even in the power saving mode, power is supplied to thecontroller 16 and the photosensitive sensor 20. If the detection signalof the photosensitive sensor 20 is received in the power saving mode,the controller 16 switches the power supply mode to a higher normalmode. If the detection signal of the photosensitive sensor 20 isreceived in the normal mode state, the controller 16 postpones switchingthe power supply mode to a lower power saving mode. The power supplymode may be set to three or more stages.

In the first state illustrated in FIG. 5 , since the first optical axis31 is parallel to the Y direction, the first detection distance Da ofthe photosensitive sensor 20 is long. In the first state, thephotosensitive sensor 20 also detects a person away from the imageforming device 1. By switching the sensor unit 19 from the first state,the detection distance of the photosensitive sensor 20 changes.

FIG. 6 is aside cross-sectional view of the sensor unit in the secondstate. FIG. 7 is an explanatory diagram of the detection range of thesensor unit in a second state. If the lever 49 illustrated in FIG. 1pivots, the photosensitive sensor 20 pivots to a position of the secondstate illustrated in FIG. 6 . In the second state, the second slit 42 isarranged on the first optical axis 31 and the third slit 43 is arrangedon the second optical axis 32. In other words, in the second state, thefirst optical axis 31 passes through the second slit 42 and the secondoptical axis 32 passes through the third slit 43. The first optical axis31 is inclined from the −Y direction to the +θ direction. As illustratedin FIG. 7 , the first detection range 51 in the second state is a finiterange. In the first detection range 51, the position farthest from theimage forming device 1 in the −Y direction is a second detectiondistance Db of the photosensitive sensor 20. The second detectiondistance Db in the second state is shorter than the first detectiondistance Da. If a person is within the range of the second detectiondistance Db, the photosensitive sensor 20 outputs a detection signal.

In the second state, the second optical axis 32 is inclined from the −Ydirection to the +θ direction. The second detection range 52 is closerto the image forming device 1 than the first detection range 51. Thephotosensitive sensor 20 outputs a detection signal even if a person iswithin the second detection range 52.

FIG. 8 is aside cross-sectional view of the sensor unit in a thirdstate. FIG. 9 is an explanatory diagram of the detection range of thesensor unit in the third state. If the lever 49 illustrated in FIG. 1pivots, the photosensitive sensor 20 pivots to the position of the thirdstate illustrated in FIG. 8 . In the third state, the third slit 43 isarranged on the first optical axis 31. In other words, in the thirdstate, the first optical axis 31 passes through the third slit 43. Thefirst optical axis 31 is inclined from the −Y direction to the +θdirection. As illustrated in FIG. 7 , the position farthest from theimage forming device 1 in the −Y direction within the first detectionrange 51 is a third detection distance Dc of the photosensitive sensor20. The third detection distance Dc in the third state is shorter thanthe first detection distance Da and the second detection distance Db. Ifa person is within the range of the third detection distance Dc, thephotosensitive sensor 20 outputs a detection signal.

As described in detail above, the sensor unit 19 of the embodimentincludes the photosensitive sensor 20, the cover 18, and the movingmechanism 48. The photosensitive sensor 20 includes the first lens 21and the second lens 22 which focus on the photosensitive elements 26 and27. The cover 18 has the first slit 41 arranged on the first opticalaxis 31 of the first lens 21 and the second slit 42 arranged on thesecond optical axis 32 of the second lens 22. The moving mechanism 48can move the photosensitive sensor 20 so that the second slit 42 isarranged on the first optical axis 31 of the first lens 21.

Since the slits 41 and 42 are elongated, the photosensitive sensor 20 isprotected from dirt. Since the incident light rays on the photosensitivesensor 20 pass through the slits 41 and 42, the attenuation of theincident light rays is prevented. Such configurations prevent thedecrease in the detection sensitivity of the photosensitive sensor 20.The moving mechanism 48 changes the slit arranged on the first opticalaxis 31. The detection range of the photosensitive sensor 20 differsdepending on whether the first optical axis 31 passes through the firstslit 41 or the second slit 42. Such configuration allows the detectionrange to be adjusted by the photosensitive sensor 20. The detectionrange can be adjusted with a simple configuration and the cost of thesensor unit is reduced.

The photosensitive sensor 20 further includes the third lens 23. Thecover 18 further has the third slit 43 located on the third optical axis33 of the third lens 23. The moving mechanism 48 can move thephotosensitive sensor 20 so that the second slit 42 is arranged on thefirst optical axis 31 of the first lens 21 and the third slit 43 isarranged on the second optical axis 32 of the second lens 22. The movingmechanism 48 can move the photosensitive sensor 20 so that the thirdslit 43 is arranged on the first optical axis 31 of the first lens 21.

The moving mechanism 48 changes the slit arranged on the first opticalaxis 31. The detection range of the photosensitive sensor 20 differsdepending on whether the first optical axis 31 passes through the firstslit 41, the second slit 42, or the third slit 43. Such configurationallows the detection range of the photosensitive sensor 20 to beadjusted.

The first lens 21, the second lens 22, and the third lens 23 arearranged side by side in the circumferential direction of the horizontalaxis H. The moving mechanism 48 is configured to pivot thephotosensitive sensor 20 around the horizontal axis H.

By pivoting the photosensitive sensor 20, the detection range can beeasily adjusted. The first optical axis 31 is perpendicular to thehorizontal axis H. Due to the pivoting of the photosensitive sensor 20,the first optical axis 31 pivots around the horizontal axis H. Suchconfiguration changes the detection range of the photosensitive sensor20 in the direction of approaching or separating from the horizontalaxis H of the photosensitive sensor 20.

The inner surface of the first slit 41 is formed along the angle of viewof the first lens 21 arranged so that the first optical axis 31 passesthrough the first slit 41. The inner surface of the second slit 42 isformed along the angle of view of the second lens 22 arranged so thatthe second optical axis 32 passes through the second slit 42. The innersurface of the third slit 43 is formed along the angle of view of thethird lens 23 arranged so that the third optical axis 33 passes throughthe third slit 43.

Respective slits 41, 42, and 43 do not limit the angles of view of thelenses 21, 22, and 23. The incident light rays on the photosensitivesensor 20 are not limited by the plurality of slits 41, 42, and 43. Suchconfiguration prevents a decrease in the detection sensitivity of thephotosensitive sensor 20.

The image forming device 1 of the embodiment includes the sensor unit19, the image forming unit 13, and the controller 16. The image formingunit 13 forms an image. The controller 16 controls the power supplied tothe image forming unit 13 based on the output signal of thephotosensitive sensor 20.

The sensor unit 19 sensitively detects a presence of a person. Thesensor unit 19 can adjust the detection range. The controller 16controls the power supplied to the image forming unit 13 based on thedetection of a person by the photosensitive sensor 20. The image formingdevice 1 can appropriately control the power supplied to the imageforming unit 13.

The photosensitive sensor 20 of the embodiment includes three lenses 21,22, and 23 and the cover 18 has three slits 41, 42, and 43. The numbersof lenses and slits are not limited thereto. The photosensitive sensor20 may include two lenses, or may include four or more lenses. The cover18 may have two slits, or may have four or more slits.

The moving mechanism 48 of at least one embodiment pivots thephotosensitive sensor 20 in a state where the cover 18 is fixed. Themoving mechanism 48 may pivot the cover 18 in a state where thephotosensitive sensor 20 is fixed. The moving mechanism 48 may pivot thephotosensitive sensor 20 and the cover 18 in opposite directions to eachother. The moving mechanism 48 can move the photosensitive sensor 20 andthe cover 18 relative to each other. In other words, the movingmechanism 48 is capable of pivoting at least one of the photosensitivesensor 20 or the cover 18.

The image processing device of at least one embodiment is the imageforming device 1 and the image processing unit is the image forming unit13 having the fixing device 14. The image processing device (processor)may be a decoloring device and the image processing unit may be an imagedecoloring unit including a decoloring portion. The image decoloringunit performs a process of decolorizing the image formed on the sheetwith decolorable toner. The decolorizing portion heats and decolorizesthe decolorable toner image formed on the sheet passing through a nip.

According to at least one embodiment described above, the sensor unit 19includes the photosensitive sensor 20 including a plurality of lenses,the cover 18 having a plurality of slits, and the moving mechanism 48for relatively moving the photosensitive sensor 20 and the cover 18. Asa result, it is possible to prevent a decrease in the detectionsensitivity of the photosensitive sensor 20 and the detection range canbe adjusted.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of thedisclosure. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the disclosure.

What is claimed is:
 1. An image processing device, comprising: aninfrared sensor including a first lens and a second lens which focus onan element; a cover having a first slit and a second slit, the firstslit arranged on an optical axis of the first lens, the second slitarranged on an optical axis of the second lens; a moving mechanismconfigured to relatively move the infrared sensor and the cover so thatthe second slit is arranged on the optical axis of the first lens; animage processor configured to process an image; and a controllerconfigured to control power supplied to the image processor, and tocontrol the image processor to switch to a normal mode in which allpower necessary for the image processor is supplied when a detectionsignal of the infrared sensor is received in a power saving mode inwhich power supplied to a part of the image processor is limited.